System and method for determining a state of health of a power source of a portable device

ABSTRACT

A method for determining a State of Health (SoH) of a power source of a portable device involves extracting a start voltage value of an examined power source; activating one or more hardware components of the portable device by a software, to increase the current consumption of the device, identifying a voltage drop rate of the examined power source and comparing a calculated voltage drop rate to pre-calculated threshold values stored on a database of a main server. A system for executing the method is also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/187,366, filed Feb. 24, 2014, which is hereby incorporated byreference.

BACKGROUND OF THE INVENTION

Mobile devices are dependent upon their batteries' life time.Approximately 20% of all customer complaints regarding portable devicesare battery related. However, 80% of replaced batteries are found tohave good State of Health (SoH).

Some known methods and systems for determining a SoH of a batteryrequire long battery inspection terms and provide poor accuracy andreliability.

For example, internal impedance check, also known as Ohm test, has verypoor accuracy and often provides different results for the same battery.Furthermore, impedance check is not reliable for Li-ion batteries.

Self-discharge check takes a very long time (e.g., approximately 50hours for Lithium Ion batteries). Prime check requires approximately 24hours.

Furthermore, known methods and systems require removing the battery fromthe device that it powers. However, more and more portable devices havean integral power source, and thus removing the power source from theportable device may damage the device.

Known systems and methods for determining the SoH of a battery requireunique testing equipment, are expensive, and require setting fordifferent types of batteries. Another disadvantage of known systems andmethods is that adapters are required for each type of battery. User nonreplaceable batteries, such as iPhone batteries, Nexus batteries and thelike, have unique connectors and thus do not have suitable adaptors.

Finally, known testing equipment require routine maintenance which istime consuming and may be expensive.

SUMMARY OF THE INVENTION

The present invention provides a system and method for determining thestate of health of a power source of a portable device.

According to some embodiments of the present invention, a method fordetermining a State of Health (SoH) of a power source of a portabledevice may comprise extracting at least one device parameter from theportable device, such as power source type; power source designcapacity; power source model; portable device model; and manufacturerdetails.

The method further comprises obtaining a start voltage value of theexamined power source and a time stamp indicative of the time the startvoltage value is obtained; activating hardware components of theportable device to increase current consumption of the device;identifying at least a first voltage drop relative to said start voltagevalue; calculating, based on pairs of consecutive voltage drops avoltage change value; comparing the calculated voltage change value ofsaid power source to threshold values stored in a database; anddetermining the State of Health of the power source based on thecomparison of the calculated voltage change value and the thresholdvalues.

According to some embodiments, the method may further compriseidentifying at least a second voltage drop relative to the first voltagedrop; calculating, based on the second voltage drop and the firstvoltage drop a second voltage drop rate of the power source; andcalculating the voltage change value based on a derivative of thevoltage in time.

According to some embodiments, the activating of the hardware comprisesactivating one or more hardware components of the portable device,selected from a group consisting: a processor of the portable device; adisplay of the portable device; a flashlight of the portable device; anda Global Positioning System (GPS) of the portable device.

According to some embodiments, the identification of the at least firstvoltage drop and the at least second voltage drop comprises reading inpredefined time intervals, a voltage file of an operation system of theportable device.

The method, according to some embodiments, may further comprise checkingthat at least one prerequisite is met prior to obtaining the startvoltage value. The at least one prerequisite may be selected from agroup consisting of: state of charge of the power source; ambienttemperature and disconnection of examined power source from a charger.

According to some embodiments, the ambient temperature may be between10-35 Celsius degrees. The state of charge may be in the range of30%-80%.

According to some embodiments, at least one of the threshold values maybe calculated based on at least one of: a mean voltage drop rate andstandard deviation of a first cluster of power sources known to have agood state of health; a mean voltage drop rate and standard deviation ofa second cluster of power sources known to have a bad state of health;and clustering algorithm. According to some embodiments, the clusteringalgorithm may be a static clustering algorithm. According to otherembodiments, the clustering algorithm may be a dynamic clusteringalgorithm (i.e., a clustering algorithm that continuously updates theclusters based on new observations).

According to some embodiments at least another of the threshold valuesequals the first threshold value multiplied by a coefficient. Accordingto some embodiments, the coefficient may be in the range of 1.25-1.90.According to other embodiments, the coefficient value may be 1.61.

A system for determining a SoH of a power source of a portable device isalso provided. According to embodiments of the present invention, thesystem may comprise at least one portable device; and a main server. Theportable device may comprise: a processor; a non-transitory computerreadable memory; a power source; and a communication unit. The mainserver may comprise a main processor; a database; and a maincommunication unit.

According to some embodiments, the at least one portable device and themain server are in active communication over a network; and the memorycomprises a software adapted to activate a plurality of hardwarecomponents of the portable device, and the processor is adapted tocalculate at least one voltage drop rate and communicate the calculatedvoltage drop rate to the main server over the network.

According to some embodiments, the main processor is adapted to comparethe received calculated voltage drop rate to threshold values stored inthe database and return to the portable device a State of Health of saidpower source, based on the comparison.

According to some embodiments, the portable device may further comprisea display adapted to display the SoH of the power source.

According to some embodiments, the portable device may further comprisea clock. According to some embodiments, the portable device may furthercomprise a temperature sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter regarded as the invention is particularly pointed outand distinctly claimed in the concluding portion of the specification.The invention, however, both as to organization and method of operation,together with objects, features, and advantages thereof, may best beunderstood by reference to the following detailed description when readwith the accompanying drawings in which:

FIG. 1 is a flowchart of a method for determining the State of Health(SoH) of a portable power source, such as a battery, according to oneembodiment of the present invention;

FIG. 2 is a flowchart of a prerequisites check that may precede themethod described with reference to FIG. 1 above, according toembodiments of the present invention; and

FIG. 3 is a block diagram of a system for determining the SoH of a powersource according to embodiments of the present invention.

It will be appreciated that, for simplicity and clarity of illustration,elements shown in the figures have not necessarily been drawn to scale.For example, the dimensions of some of the elements may be exaggeratedrelative to other elements for clarity. Further, where consideredappropriate, reference numerals may be repeated among the figures toindicate corresponding or analogous elements.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of the invention.However, it will be understood by those skilled in the art that thepresent invention may be practiced without these specific details. Inother instances, well-known methods, procedures, and components have notbeen described in detail so as not to obscure the present invention.

Referring to FIG. 1, a flowchart of a method for determining the stateof health of a portable power source, such as a battery, according toone embodiment of the present invention is presented.

According to embodiments of the present invention, when a State ofHealth (SoH) test is initiated (block 1010), a timer may be started(block 1015) in order to indicate the duration of the SoH test. Itshould be appreciated, however, that this stage may not be required inall embodiments of the present invention, and that the test duration maybe obtained from an internal clock of the device or from a network suchas the internet.

After the timer is started, different parameters may be extracted fromthe portable power source (e.g., a battery) of the examined portabledevice (block 1020). For example, a start voltage of the portable devicebattery may be extracted and recorded in a memory of the portabledevice. According to some embodiments, the start voltage may be recordedin a memory together with a time stamp indicating the time of extractingof the start voltage.

According to some embodiments, one or more additional parameters may beextracted and recorded on a memory (e.g., a non-transitory computerreadable medium such as a memory card of the portable device), such asambient temperature at the beginning of the test; SoC of power source atthe beginning of the test; design capacity of the power source; portabledevice type (e.g., smart phone, tablet computer, smart watch, etc.);number of cores of Central Processing Unit (CPU) in the portable device;consumption of current of portable device; portable device's model andmanufacturer parameters. It should be appreciated by those skilled inthe art that other or additional parameters may be obtained from theportable device. It should be further realized that the extractedparameters may be monitored and recorded by the Operation System (OS) ofthe device as part of its regular operation. However, according to someembodiments, some of the extracted parameters may not be routinelyextracted and recorded by the OS and may be extracted only for thepurpose of the SoH test.

After the required start parameters have been extracted and recorded,the portable device's hardware may be electrically loaded (block 1030)by activating software programs installed on the portable devicecharacterized by relatively high current consumption, in order tomaximize current consumption during the time of the SoH test. Accordingto an embodiment of the present invention, software may be run on allcores of the CPU in order to load the portable device. According to someembodiments, the software may be byte oriented software, such as MD5Hash or other encryption software. It should be appreciated by thoseskilled in the art that other software may be used.

According to some embodiments, the loading stage (block 1030) mayprecede the parameters extracting stage (block 1020). According to someembodiments, the loading stage may continuously proceed during theentire process. According to other embodiments, the loading stage may benon-continuous.

According to some embodiments, in addition to or instead of loading theCPU of the portable device, other hardware may be operated in order toobtain high load of the power source. For example, while running byteoriented software on all cores of the CPU, the screen of the portabledevice may be illuminated in white light with a high brightness level.In another example, a Global Positioning System (GPS) may be activatedin conjunction with or instead of one or more of other hardwarecomponents of the portable device, in order to load the device.According to yet another example, the flashlight of the device may beactivated in conjunction with or instead of other hardware components inorder to load the portable device. It should be appreciated that otheror additional hardware elements of the portable device may be operatedin order to load the device.

During loading of the device, voltage files may be read from theOperation System (OS) running on the device (block 1040). According tosome embodiments of the present invention, reading of voltage files maybe conducted every predefined time interval, such as every 500milliseconds, until at least one voltage drop is identified (block1050). It should be appreciated that a voltage drop may be a decrease inthe voltage of the power source with respect to a previous voltagereading.

According to some embodiments, voltage drops may be identified bycomparing consecutive readings of voltage files from the OS of thedevice. A voltage drop would be identified between two consecutivereadings of voltage files, when the voltage in earlier reading is higherthan the reading in the later reading.

According to some embodiments, a baseline for voltage drop check may beset as the voltage of the power source at the time of the firstidentified voltage drop. After the voltage baseline has been set, atleast another voltage drop is awaited (block 1050). According toembodiments of the present invention, each voltage level at each voltagedrop is recorded. In addition, a time stamp may be assigned to eachvoltage level at each voltage drop (block 1060).

According to some embodiments, the start voltage extracted at theproperties extraction stage (block 1020) may be used as the baseline fordetermining voltage drop. Thus, it should be appreciated that a singlevoltage drop may be sufficient in order to determine the SoH of anexamined battery or other power source.

According to some embodiments of the present invention, additional testof end parameters may be obtained and stored (block 1060). For example,test of end parameters may comprise end voltage of power source; a timestamp; ambient temperature at the end of the test; total currentconsumption; and other parameters from the portable device.

After at least one voltage drop has been observed and recorded, and endparameters has been extracted, a check may be conducted to determinewhether a predetermined timeout period has elapsed (block 1070) from thebeginning of the test. If the preset timeout period has not elapsed,steps 1020 to 1060 may be repeated to obtain additional test results andthus improve the accuracy of the SoH determination.

When the preset timeout period elapses, the data collection stage ends(block 1090). It should be appreciated that the data collected (i.e.,observations of the voltage of the power source and the time ofobservation) during the test may serve as the raw data for calculationand determination of the SoH of a power source.

According to some embodiments of the present invention, a check of theobservations may be conducted to verify that the observed data issufficient and is informative (block 1080). For example, at this stage acheck may be conducted to verify that the identified voltage drop islarger than a predefined threshold. According to some embodiments, acheck for identifying abnormal observations may also be conducted atthis stage. For example, if an observation shows an increase in thevoltage with respect to a previous observation, or with respect to thebaseline voltage, such an observation may not be taken intoconsideration in the determination of the SoH of the power source.

According to some embodiments of the present invention, if the checkconducted in block 1080 indicates that the recorded observations areinsufficient in order to complete the SoH determination (e.g.,insufficient voltage drop during observation or abnormal observation)the test may be repeated. According to some embodiments, an error noticemay be displayed on a display of the portable device (block 1095),indicating that an error has occurred, and may allow the user to decidewhether to repeat the test or not.

After the data collection stage ends (block 1090), a power source healthdetermination stage begins (block 1100). The power source healthdetermination stage or SoH determination stage comprises, according tosome embodiments of the present invention, calculating the voltagechange rate for each observation (block 1110). According to someembodiments, the calculation of the voltage change rate may be done bycalculating the slope of the voltage drop curve as may be derived fromthe data obtained for two consecutive observations, for example bycalculating a derivative of the voltage in time. It should be realizedthat, for the first observation, the calculation of the slope of thevoltage drop curve is done with respect to the start voltage of thepower source extracted at block 1020 or with respect to the baselinevoltage set after the observation of a first voltage drop.

After the voltage change in time is calculated for each pair ofconsecutive observations, a Maximal Voltage Change (MVC) may becalculated (block 1120). It should be appreciated by those skilled inthe art that the MVC is the observation with the largest voltage drop ina given time interval.

According to other embodiments, an Average Voltage Change (AVC) may beused. AVC value may be a weighted average of the voltage drop ratescalculated in block 1110. According to one embodiment, each voltage droprate value may be assigned a different weight according to differentcriteria. For example, as the time that elapsed from the beginning ofthe test is longer, the voltage drop rate value may get a higher weight.

According to some embodiments of the present invention, all voltage droprates may receive the same weight in the calculation of the AVC value.It should be further appreciated that, when the weight assigned to themaximal voltage change observation is 1, the AVC value will be equal tothe MVC value.

According to some embodiments, the calculated value (i.e., the MVC valueand/or the AVC value) may be compared to threshold values stored in adatabase. The threshold values may be pre-calculated and pre-storedthreshold values calculated based on power sources having a known stateof health. For example, in a preliminary stage, a large number ofreference power sources may be checked in a full cycle SoH test (e.g.,approximately 24-48 hours) and each reference power source may beclustered to a cluster according to its measured capacity. For example,if a reference power source has a measured capacity in a full cycle testof less than 80% of the design capacity of the reference power source,this reference power source may be clustered as a bad SoH power source.For each created cluster of reference power sources, the mean voltagedrop rate and standard deviation may be calculated and stored in adatabase.

According to some embodiments of the present invention, a bad SoHthreshold and a good SoH threshold may be set according to the followingformulas:

TH _(bad)=μ_(bad)−ασ_(bad)   (1)

TH _(good)=μ_(good)+βσ_(good)   (2)

Where:

-   μ_(bad) is the mean of voltage drop rate for power sources known to    have a bad SoH;-   μ_(good) is the mean of voltage drop rate for power sources known to    have a good SoH;-   α, β are power source coefficients;-   σ_(bad) is the standard deviation of voltage drop rate of power    sources known to have a bad SoH; and-   σ_(good) is the standard deviation of voltage drop rate of power    sources known to have a good SoH.

According to some embodiments, α and β may be selected based on the typeof power source, the type of device, the model of the power source orthe portable device, the manufacturer of the power source or the device,and/or other parameters such as the tolerance to false results etc. Itshould be appreciated that α and β may be different or may be equal.

According to another embodiment, only a first of the thresholds may becalculated according to one of formulas (1) and (2) above, while theother threshold may be calculated as a function of the first thresholdaccording to the following formula:

TH_(bad)=λTH_(good)   (3)

It should be understood that λ may receive any value equal to or higherthan 1. For example, when λ=1, a single threshold is set, and allexamined power sources may be determined to be either in good SoH or inbad SoH. When λ is larger than 1, there are two thresholds and a powersource may thus be determined to be either in good SoH, in bad SoH or infair SoH.

Experiments conducted according to embodiments of the present inventionshow that when λ is in the rage of 1.25-1.90, a reliable determinationof the SoH of a power source may be achieved based on the thresholds setaccording to formulas (1) and (3) above. For example, using λ=1.61results in a SoH determination over 90% confidence.

After the calculated voltage drop value for an examined power source hasbeen calculated, the MVC or AVC value may be compared to the thresholdsfor bad SoH (THbad) and for good SoH (THgood) stored in the database todetermine the SoH of the examined power source (block 1130). If thecalculated value is lower than THbad, then the SoH of the examined powersource may be determined to be bad. If the calculated value is higherthan THgood, then the SoH of the examined power source may be determinedto be good. If the calculated voltage drop value is between THbad andTHgood, then the SoH of the examined power source may be determined tobe fair.

According to some embodiments, a plurality of thresholds may becalculated using different α, β and λ values. When a plurality ofthresholds is used, the SoH of a power source may be determined in amore precise manner For example, calculating a first threshold usingformula (1) with a small α and a second threshold using formula (1) witha larger α, may provide an indication as to how bad is the SoH of thepower source. If, for example, the MVC of the power source is higherthan the first threshold, than it may be determined that the state ofhealth of the power source is very bad. If the MVC is between the firstand second thresholds than the SoH of the power source may be determinedto be bad. Similarly, calculating additional thresholds may allowdetermining the SoH of a power source to be fair-bad SoH, fair-good SoH,good SoH and so on.

According to other embodiments, clustering algorithms, such as K-meansclustering algorithm, 1-R clustering algorithm and the like, may beapplied to a large number of reference power sources in order to createdifferent clusters of reference power sources according to their SoH.After creating clusters for different States of Health based on thereference power sources, statistical tests, such as T-test, may beapplied to determine how reliable the clusters are, and whether a newclustering process should be applied to update the clusters.

According to some embodiments of the present invention, after the SoH ofan examined power source is determined, the data obtained for theexamined power source may be used in order to update the μ and σ valuesstored in the database (block 1140) and to recalculate the thresholdsfor future use. It should be appreciated that adding the examined powersource as a reference power source for future use may change theclustering of other reference power sources. For example, if theexamined power source is determined to have a good SoH, the MVC or AVCof the examined power source may be included in the recalculation ofμ_(good) and σ_(good) values, and a new TH_(good) may be calculated. Itshould be appreciated that this stage may not be required, or may beapplied only in some cases, while in other cases the MVC or AVC of anexamined power source may not be used in order to update the μ and σvalues stored in the database or in order to re-cluster the referencepower sources.

According to some embodiments, the determined SoH of an examined powersource may be presented on display of the portable device (block 1150).According to some embodiments, a recommendation may be presented, suchas replace power source, check battery usage, check recharger, and thelike, instead or in addition to the indication of the SoH of theexamined power source.

Reference is now made to FIG. 2, which is a flowchart of a prerequisitescheck that may precede the method described with reference to FIG. 1above, according to embodiments of the present invention.

According to one embodiment of the present invention, an initial checkthat the examined battery or other examined power source meetspredefined prerequisites may be conducted (block 2020). For example, itmay be required that the examined battery be disconnected from anexternal power source, such as a battery charger, before proceeding tothe next stage (block 2020 a).

An additional or alternative prerequisite may be the ambient conditionsin which the examined battery is checked. For example, it may berequired that the ambient temperature will be higher than a minimaltemperature threshold and/or not lower than a maximal temperaturethreshold (block 2020 c). According to one embodiment of the presentinvention, the minimum temperature threshold may be 10° C. (degreesCelsius), and the maximal temperature threshold may be 35° C. It shouldbe appreciated by those skilled in the art that the maximal and minimaltemperature thresholds may change according to the specific type ofbattery, other ambient conditions, type of battery and the like.

According to some embodiments, the State of Charge (SoC) may also serveas a prerequisite for initiating the battery SoH determination process(block 2020 b). Typically, the voltage drop curve of a battery, such asa single cell battery, may be divided into a first rapid drop region, apseudo linear region and a second rapid voltage drop region. Since itmay be desirable to conduct the battery's SoH check within the pseudolinear region of the voltage drop curve, a prerequisite of a SoC betweena minimal bound and a maximal bound may be determined.

For example, a SoC between 30% and 80% may be determined in order toensure that the examined battery is in the pseudo linear region of thevoltage drop curve. It should be appreciated that SoC bounds may bedetermined according to the type of battery, the type of device, the ageof the battery, etc.

As seen in block 2030 in FIG. 2, a recommendation to disconnect theportable device from external power sources may be presented on adisplay of the portable device. According to some embodiments, insteador in addition to presenting a recommendation to disconnect the externalpower source, the v-bus of the portable device may be automaticallydisconnected and a check whether the portable device is disconnectedfrom an external power source (e.g., a battery charger) is conducted(block 2040).

According to some embodiments of the present invention, after the factthat the examined power source is disconnected from an external powersource is verified, a check may be conducted whether other prerequisitesare met (block 2050). When one or more of the prerequisites is not met,a recommendation or guidance as to how to meet the unmet prerequisitemay be presented (e.g., on a display of the portable device) (block2060). For example, if the preliminary check indicates that the SoC isbelow the minimum threshold, an indication may be presented and arecommendation to charge the portable device may be displayed on adisplay of the device. It should be appreciated that other instructionsand guidance may be provided, according to the unmet prerequisite.

When all prerequisites are found to be met, the process may proceed tothe SoH determination stage (block 2070).

Reference is now made to FIG. 3, which is a block diagram of a system300 for determining the SoH of at least one power source, such asbattery 36, of at least one portable device 30.

According to some embodiments of the present invention, system 300 maycomprise one or more portable devices 30 and at least one main server40. Main server 40 may be in active communication with one or moreportable device 30 over a network 50, such as the internet or a cellularcommunication network. It should be appreciated that other networks maybe used.

According to some embodiments of the present invention, portable device30 may comprise a display 32, such as a touch screen, a CentralProcessing Unit (CPU) 34, and a non-transitory computerreadable/writable medium, such as memory 38.

According to some embodiments, portable device 30 may further comprise acommunication unit 35 for communicating via network 50 with otherdevices and systems such as main server 40. According to yet otherembodiments, portable device 30 may further comprise an input unit 37,such as a keypad, microphone and the like. It would be appreciated thatwhen display 32 is a touch screen, display 32 may be integrated withinput unit 37.

In some embodiments of the present invention, portable device 30 mayfurther comprise one or more of: a clock 39; a temperature sensor 31; aGlobal Positioning System (GPS) unit (not shown); and a power inlet 33for charging battery 36 from an external power source (not shown). Itshould be appreciated by those skilled in the art that portable device30 may comprise other and additional components such as a loudspeakers,camera, and a plurality of hubs and connectors (not shown).

According to some embodiments, when a SoH determination test isrequired, CPU 34 of device 30 may be electrically loaded (i.e., operatedto consume high current) and display 32 may be illuminated (e.g., inwhite light with high brightness). Information regarding voltage dropduring loading of device 30 may be obtained from the operation systemstored in memory 38. Clock 39 may provide time stamps for each readingof voltage.

According to some embodiments, CPU 34 may be adapted to calculate theslope of the voltage drop curve based on consecutive voltageobservations, and may calculate a maximal voltage change rate value. Thecalculated voltage change rate value (MVC) and/or the observationsrecorded on memory 38, may be communicated to server 40 over network 50.

According to some embodiments of the present invention, main server 40may comprise a processor 44, a database 48 and a server communicationunit 45. Processor 44 may be adapted to receive voltage dropobservations and/or calculated voltage drop values such as MaximalVoltage Change (MVC) or Average Voltage Change (AVC) value from portabledevice 30 over network 50 and to calculate and determine the State ofHealth (SoH) of battery 36 based on a comparison of the receivedcalculated voltage drop value with pre-calculated thresholds stored indatabase 48.

According to embodiments of the present invention, after the SoH ofbattery 36 has been determined, the SoH may be returned to portabledevice 30 via server communication unit 45.

While certain features of the invention have been illustrated anddescribed herein, many modifications, substitutions, changes, andequivalents will now occur to those of ordinary skill in the art. It is,therefore, to be understood that the appended claims are intended tocover all such modifications and changes as fall within the true spiritof the invention.

1. A method for determining a State of Health (SoH) of a power source ofa portable communication device, the method comprising: extracting, witha processor of the portable communication device, at least one deviceparameter from said portable communication device; obtaining fromvoltage files of an Operation System (OS) running on the portablecommunication device, with the processor, a start voltage value of saidpower source and a time stamp indicative of the time said start voltagevalue is obtained; activating, with the processor, software componentsinstalled on said portable communication device to electrically loadhardware of said device; identifying, with the processor, at least afirst voltage drop relative to said start voltage value by comparingconsecutive readings of voltage files from the OS of the portablecommunication device; calculating, with the processor, based on pairs ofconsecutive voltage readings a voltage change value; comparing, with theprocessor, said calculated voltage change value of said power source tothreshold values stored in a database; and determining, with theprocessor, said State of Health of said power source based on saidcomparison of said calculated voltage change value and said thresholdvalues.
 2. The method according to claim 1 further comprising:identifying at least a second voltage drop relative to said firstvoltage drop by comparing consecutive readings of voltage files from theOS of the portable communication device; calculating, based on saidsecond voltage drop and said first voltage drop a second voltage droprate of said power source; and calculating said voltage change valuebased on a derivative of the voltage in time.
 3. The method according toclaim 1 wherein said hardware activated by the software componentscomprises one or more of: a display of said portable communicationdevice; a flashlight of said portable communication device; and a GPS ofsaid portable communication device.
 4. The method according to claim 1further comprising checking that at least one prerequisite is met priorto obtaining said start voltage value.
 5. The method according to claim4 wherein said at least one prerequisite is any of: state of charge ofsaid power source; ambient temperature and disconnection of examinedpower source from a charger.
 6. The method according to claim 5 whereinsaid ambient temperature is between 10-35 Celsius degrees.
 7. The methodaccording to claim 6 wherein said state of charge is in the range of30%-80%.
 8. The method according to claim 1 wherein at least one of saidthreshold values is calculated based on at least one of: a mean voltagedrop rate and standard deviation of a first cluster of power sourcesknown to have a good state of health; a mean voltage drop rate andstandard deviation of a second cluster of power sources known to have abad state of health; and clustering algorithm.
 9. The method accordingto claim 8, wherein at least another of said threshold values equalssaid one threshold value multiplied by a coefficient.
 10. The methodaccording to claim 9, wherein said coefficient equals 1.61.
 11. Themethod according to claim 1, wherein said at least one device parameteris any of: power source type; power source design capacity; power sourcemodel; portable communication device model; and manufacturer details.12. The method according to claim 1, further comprising repeating thesteps of: obtaining from voltage files of the OS additional startvoltage values of said power source and time stamps indicative of thetime said start voltage value is obtained; identifying, with theprocessor, at least additional voltage drops relative to said startvoltage value; calculating, additional voltage change values; comparing,with the processor, said additional calculated voltage change values ofsaid power source to threshold values stored in a database; anddetermining, with the processor, said State of Health of said powersource based on said comparison of said additional calculated voltagechange value and said threshold values.
 13. A system for determining aState of Health (SoH) of a power source of a portable communicationdevice, comprising: at least one portable communication device; and amain server; wherein said portable communication device comprises: aprocessor; a non-transitory computer readable memory; a power source;and a communication unit; wherein said main server comprises: a mainprocessor; a database; and a main communication unit; wherein said atleast one portable communication device and said main server are inactive communication over a network; and wherein said memory comprisessoftware adapted to electrically load one or more hardware components ofsaid device, and said processor is adapted to calculate at least onevoltage drop rate of the power source by comparing consecutive readingsof voltage files from the operating system of the mobile communicationdevice and communicate said calculated voltage drop rate to said mainserver over said network; and wherein said main processor is adapted tocompare said received calculated voltage drop rate to threshold valuesstored in said database and return to said portable communication devicea State of Health of said power source, based on said comparison. 14.The system according to claim 13 wherein said portable communicationdevice further comprises a display adapted to display said SoH of saidpower source.
 15. The system according to claim 13 wherein said portablecommunication device further comprises a clock.
 16. The system accordingto claim 13 wherein said portable communication device further comprisesa temperature sensor.